Marius the giraffe was a surplus animal, from the Copenhagen Zoo’s perspective. His genes were common within the facility’s breeding program, so he could not be allowed to mate with females because of the risk of inbreeding. He died February 9 from a shot to the head with a bolt gun.

A furor erupted after Marius was killed, necropsied and fed to lions. Whatever you think about the case of Marius or how the zoo handled it, his death brings to light a different way of thinking in U.S. versus Eur...